Method of and apparatus for geological exploration



SQL E2? @3 W, 1 TAYLOR, JR gg'g METHOD 0F AND APPARATUS FOR GEQLOGICALEXPLORATION Filed March l, 1937 2 ShGeJS-Sh'eet 1 @aml/ Sept l2, E939;ZZ@

METHOD oF AND APPARATUS FOR GEOLOGIGAI.-` EXPLORATION W. J. TAYLQR, JR

2 Sheets-Sheet 2 Filed March l, 1937 Patented sepf.12',1939 ,y i2,172,778 j UNITED STATES PATENT OFFICE METHOD or AND APPARATUS Foa GEO-I LOGICAL EXPLORATION .i Y William JosiahA Taylor, Jr., Shreveport, La.

ApplicationI March 1, 1937, Serial No'. 128,514

' 11 claims. (ci. 11s-Isc) This invention relates to an improvement in Ihere propose' t0 Ineke use 0l' thechnnge in. the art of the explorationof )the crust of the galvanic action with time by measuring the timeearth by a method of passing electric currents element as Vweil as theelectrical quantities, and through the earths crust by means oi one ormore using the data thus obtained to correct for such electrodes of a.certain new type in electrical con- -galvanic action or else to use suchmeasurements l5 tact with the earth, or by means of newV and speon thenatural galvanic action in the earth macial arrangements-of electrodesin electrical con terialS as a means 0f determining the character tactwith the earth, as described hereinafter, and structure of said earthmaterials. Heretowhereby measurementsmay be made upon curfore in theeri? Oi' eletlinl prospecting. an effort rents flowing through a deniteportion, or poris usually made to balance out the eiects of 10 tions, ofthe earth, or a now of current through Such galvanic action within theearth and at the the earth between similar conductors in said new Ylectrodes by reversing Current 110W. Winnen/:"1y electrodes may bedenected by applying electropropose t0 use such phenomena to advantagein motive forces to other component, conductors exploration, rather thantake steps to eliminate ofthe said electrodes. said phenomena. f I lMore specifically, the invention contemplates The exploration of aportion ofthe earth's `making comparative measurements of currents Crustunderlying e given aree as DroDOSed herein directed, by my improvedelectrode arrangement, is carried on in one oi' the following, or in anythrough the surface strata and through the enmbinaiion'of the fOiiOWinS,.WBYSI by en ardeeper strata, respectively, and thus determiningrangement of multiple conductor electrodes, each 20 their relativecharacteristics. consisting of a plurality of mutually insulated A pairof special electrodes or a special con- Y conductors. and by PassingCurrent through all figuration of electrodes is here proposed to acofthe conductors and through the earths crust, y complish this. Eachspecial 1 electrode consists and comparing the values of the portions ofthe 2B of two or more, electrical conductors"insulatedP currents whichtravel deeper and deeper; by an from one another; but each of theconductors arrangement of multiple conductor electrodes in contact withthe earth. The electrode-toand accompanying l measuring devices, andearth contact surface of one of them can encircle sources o1'electromotivel force which are moved the contact surface ofthe others,and this type` from one location to another and reassembled will beldiscussed rst. The simplest example of with the same, spacing of theelectrodes and the 30 this type of electrode consists of a rod and atube same connection of the external circuits used at of metal arrangedconcentrically wlthlinsulating an earlier location; by a similar'arrangement material between, and Iaced" at one end to prowherein oneelectrode remains nxed and the v vide a `.good surface for makingcontact to the other one moved in such a way that the-distance ground.This contactfend might be turned between the electrodes is increasedbetween suc- 35 .conical in forni as a plumb bob or else hemicesslvereadings, whereby the currents reach spherical. The tube and rod can.alsobe ar- 'greater land greater depths 1n their passage `rangedeccentrically with insulating material bethrough the earth.`

tween. A measuring arrangement is set up using By the aforesaid means ofexploring the crust 40 these electrodes. The separate conductors of theof ythe earth by means oi' electric currents, 40

electrodes are connected to separate electrical enough observations maybe made to determine measuring devices and separate sources oielecthe-'desired `properties vor anomalies sought for tro-motive-forcethrough a lconvenient. arrangein the earth's crust,whether in structureor in ment of switches. I 'l Vmaterial.v Measurements may be made' onthe potential Iny order that the invention may be readily 45 drops, ifany, and the currents owing through understood, reference is had to theaccompanyf i l the various circuits whether the currents are ingdrawings, forming part-of this specification generated by-electro-motiveforces applied exand in which: n

ternally to the earth, or by electro-motive forces Fig. 1 is a diagramillustratingv the principles existing within the earth due to diierencesin involved in the present invention, in its simplest 50 chemicalcomposition or porosity of the earths form; g materials, or by bothsources of electro-motive- Fig. 2 is a similar diagram showing anotherforce. When currents arise `from galvanic acand more complex arrangementof apparatus emtion within the earth or from the galvanic action bodyingthe invention; of earth materials in contact with'the electrodes, Fig. 3shows, in vertical section and plan, one v55 trode which I may employ;

. with the earth, and separate wires are 2 l J form of my improvedmultiple conductor lelecrode;`

Fig. 4 shows in vertical section and perspective another form of myimproved multiple conductor electrode;

Figs. 5, 6,' 7 and 8 are views showing in vertical section and in planfour other modified forms of electrode;

Fig. 9 is a perspective other arrangement of multiple conductor elecandFigs. 10 and 11 are perspective views illustrating special arrangementsof groups 0i! separate electrodes, by means of which the invention maybe carried out. f-

Referring to the drawings tral conductor and a concentrically arrangedannular conductor, separated by insulating material. The convex orspherical surface of this electrode is designed to be placed in contactto the two conducting portions as shown.

Fig. 4 shows a further, development or carrylng forward of the sameidea. In this form, there is provided a composite electrode consistingof a central and three concentric annular coni registering the timeducting portions of progressively increasing size, all of saidconducting portions being separated from each other by insulatingmaterial, and separate wires being connected with the four conductingportions. O rle composite electrode of the form shown in Fig. 3 isillustrated at Il in the diagram of Fig. 1, while or compositeelectrodes of the form shown in Fig. 4 are illustrated at 5 in thediagram of Fig. 2.

Similar numbers refer to similar parts and devices throughout theFigures 1 and 2, illustrating the two disclosed forms of the invention.

Circuits external to the earth are designated by numbers l, 2, 3 and 4.6,6 are insulated conductors of electricity connecting conductors in amulti-conductor electrode measuring devices 8,8. In Figures 1 and 2, 1,1are an insulated conductor or conduct-ors of electricity connecting anelectrode 5 or Il to a single source il, or to a number of separatesources of electromotive force ll,il; 9,9 represent single poleswitches,l or single pole push button switches, and IILIII representdouble pole double throw switches. I2,|2 are devices for measuring orregistering potential difference. 8,8 are current measuring devices orregistering devices having suitable means for measuring or `elapsed.after closing4 the switches 9,9. 8,8'can be registering elements in anoscillo'graph having suitable means for measuring or registering timeintervals or 8,8 lcan be current measuring kdevices such as lammetersand used when convenient or necessary in conjunction with some form oi'chroncmetrically registering or measuring device such as a stop-watch,or metronome. These examples given here do not. limit the devices to thespeciilc forms of oscillograph, ammeter, stop-watch, or metronome. i|,l|are sources of electromotiveforce which may be constant or which mayvary with time in any manner necessary to the successful execution ofthe method in the particular area *being explored, i. e., theelectromotive force view illustrating stili an! in detail and Ymoreparticularly ilrst to Fig. 3 thereof, the novel elect connected A twomultiple conductor 5, or Il to current covered by water. The electrodescan be imbedded in water if the measuring instruments are out of thewater. i3 is an electrode of any convenient shape, and can consistI of apiece ot metal or a porous pot containing an electrolyte. In all of thefigures insulating materials are designated by the numbers 22,andelectrically conducting materials by 23.

The present invention is not limited to geological exploration with theparticular forms of apparatus disclosed in Figs. 1 and 2. In Fig. 1, a

composite electrode comprising two conductora' is illustrated, while inFig. 2, an electrode having four conductors is shown. The inventionis,however, nt limited to any particular number of conductors in thecomposite electrode, provided that there are more than one suchconductor. Aside from a difference in the number of branch circuits andof component conductors of the multiple-conductor electrodes, the formsofthe measuring devices disclosed in Figures 1 and 2 differ from eachother in that the second form of the two has a separate source ofelectromotive force for each branch circuit and component conductor ofthe pair of multiple /conductor electrodes 5,5, whereas the first formhas an electromotive force and external wire 1` and simple electrode I3common to the currents which iiow through both conductors of the twoconductor electrode I4.

Referring lto Fig. 1, the paths of the current through the earthareindicated by dotted lines, and lt will be seen that the current fromthe outer or annular conductor of the composite electrode Il flows alonga path'of roughly annular cross section and flows through the upperstrata nearer the surface of the earth as well as through the very deepstrata, while the curthrough the central conductor can thus be confinedto a more or less definite path at a substantially predetermined depth.By measuring the current ilowingv through each conductor of thecomposite electrode and comparing the values of such currents, therelative conductivity of the strata at different depths can beascertained and the characteristics of the different strata as regardscontent ofminerals or other material Whose conductivity is either'`greater or less than that of normal earth, may be. determined. Thearrangement in Fig. 2 is substantially similar except that as abovementioned separate sources of electromotive force are indicated, andinstead of a". composite electrode and a simple electrode as shown ifFig. 1. two composite electrodes, each comprising four conductors, areemployed. Aside from the'diierence in the number ot branch circuits andf conductors, the two disclosed arrangements in Figures 1 and 2 areequivalent in their characteristics and operation so long as onlyentirely homogeneous or perfectly horizontally stratiiled earth isexplored. If there is a lack of symmetry in the composition of the earthwith respect to a plane which is the per- Il', the two arrangements orforms will give different results. Because of this it has provedbeneficial to use sometimes one and sometimes the other form of theapparatus in conducting y explorations. Wherefore the form can not belimited to either type nor, on the other hand, can the two forms becalled entirely equivalent. A form similar to that disclosed in Figure 1is used when itis desired to search for anti-symmetricalconditions inthe composition of t e crust of the earth. When outcrops occur fequently or other lack of symmetry occurs l ally and particularly nearthe surface of the earth, it is 'often necessary touse a form of thegenerall type disclosed in Figure 2, that is, an arrangement consistingof two similar multiple conductor electrodes, and entirely separateexternal branch circuits and electromotive forces connected to eachconductor of said multiple con- 1 ductor electrodes.

In Figs. 5, 6, 7 and 8,v other forms of composite electrodes areillustrated, each of these being two lconductor electrodes like thatshown in Fig.

3. In Fig. 5, however, the end of the composite electrode which engagesthe ground is shown,

as conical instead of hemispherical, while in the other three iiguresthe lower end or face of the electrode is shown as at. Any of theseforms may be used in piace 'of that shown in Fig. 3, if desired. l

In Fig. 9,'I have illustrated a composite electrode'arrangementconsisting of a central con'- ductor I such as a rod or tube, driveninto the ground and surrounded by a piece of'wire netting l'or the like,engaging the surface ofthe ground and having a hole through -which therod |5 passes in spaced relation from the netting. The eil'ect of thiscomposite electrode on the idistril bution of current in `the earthsstrata ls similar to that of the electrode shown in Fig. 3.

In Figs. 10 and 11, I have shown methods of producing the same resultsby means of a plurality of separate conductors spaced apart and driveninto the ground. This arrangement hasf the advantage that the separateelectrodes of the group may be separated considerablev distances ifdesired. In Fig. 10, I have shown a central conductor surrounded bya'group of similar conductors electricallyunited, and so connected thatcomparative readings may be taken of the current flowing through thecentral y electrode and through the surrounding group as a suit. In Fig.11, I have shown a composite electrode formed of two groups of spacedconductors disposed in more or less parallel lines, spaced apartV asdesired, comparative readings being v`taken of the current'owing througheach group as a unit.

I claim: 1; Apparatus for electrically exploringI the earths crustcomprising a pair of earth contacting. means located one at each of thetwo separated geographical stations, at least one ci' said means.comprising a plurality of conductors spaced-*from each other,` a circuitextending from l each of said conductors at one stationA to the earthcontacting means at the other station, separate current measuring meansin each of said circuits, and means for generating an electromotiveforce in the same direction in each of said circuits.

2. Apparatus for electrically exploring the earths crust comprising apair of earth contacting means located one at each of two separatedgeographical stations. at least one of said means comprising a pluralityof conductors spaced from each other, a circuit extending from each ofsaid.

conductors at one station to the earth` contacting means at the otherstation, means for .causing current to flow in all of said'circuits inthe same direction, and means for independently measuring the amount ofycurrent flowing in eac circuit.

. -3. Apparatus as in claim`1, in which there is a common circuit'extending between stations and containing a source of electromotive'forca said common` circuit having a plurality of branches, each branchbeing connected with one of saidconductors and containing a separatecurrent measuring means. i

4. Apparatus as in claim 1 in which there are a plurality of earthcontacting conductors at each station, and in which a separate circuit,

' each containing a source of electromotive force and a currentmeasuring instrument, connects corresponding conductors at therespective Vstations.

5.In apparatus for electrically exploring theearthfs crust, earthcontacting meansy comprising a central/conductor, and conducting meanssurrounding and spaced from said 4central conductor.

6. In-apparatus for electricallyexploring the e ductor surrounding andinsulated from said central conductor, the end of said electrode beingin the formV of a solid of revolution, whereby,.

when said electrode is introduced into the earths surface, said centralconductor extends deeperl thansaidouter conductor.

8. In apparatus for electrically exploring ythe earths crust, acomposite contact electrode comprising aplurality 'of conductors spacedapart and engaging the earth, said conductors being otherwise insulatedfrom. each other, one of said conductors,` when the electrode is in use,extendingmore deeply into the earth than the otherLf, u

9. 'I'he method of electrically exploring the earths crust winchcomprises causing current to ow throughthe earth between a plurality ofassociated conductors -at one geographical station and an electrode atanother geographical station, and separately measuring the value of theportions of'such current ilowing throughy each of said conductors.

` 10. The method` of electrically exploring the `earths crust whichcomprises causing current to ilow through the earth between'an electrodeat one station and a plurality of conductors` contacting the earth. a'tdifferent depths at another station, and determining the relative valueof the portions of such current iiowing through the respectiveconductors.

11..The method of electrically exploring the earths crust Whichcomprises'causing current to flow through the earth between grpundedconductors at separated stations, and deflecting such current from itsnormal pat .1 by causing another current to flow through the earthbetween substantiallyfthe same stations in the same direction.

WILLIAM JosIAH TAYLOR, JUNIOR.

